Coke is a solid carbon fuel and carbon source used to melt and reduce iron ore in the production of steel. To make coke, finely crushed coal is fed into a coke oven and heated in an oxygen depleted environment under closely controlled atmospheric conditions. Such an environment drives off volatile compounds in the coal, leaving behind coke. In some coking plants, once the coal is “coked out” or fully coked, an oven door is opened and the hot coke is pushed from the oven into a hot box of a flat push hot car (“hot car”). The hot car then transports the hot coke from the coke oven to a quenching area (e.g., wet or dry quenching) to cool the coke below its ignition temperature. After being quenched, the coke is screened and loaded into rail cars or trucks for shipment or later use.
Over time, the volatile coal constituents (i.e., water, coal-gas, coal-tar, etc.) released during the coking process can accumulate on the interior surfaces of the coke oven, forming gummy, solidified coking deposits. As used herein, “coking deposit(s)” refers to one or more residual materials that can accumulate within the coke oven, such as, for example, clinkers, ash, and others. Such deposits can have a variety of adverse effects on coke production, including slowing and/or complicating the hot coke pushing operation, decreasing the effective dimensions of the oven, and lowering the thermal conductivity of the oven walls and/or floor. Because of such adverse effects, deposit removal (“decarbonization”) is a mandatory aspect of routine coke oven maintenance in order to maintain coke plant efficiency and yield.
To remove deposits from the coke ovens, oven operation (and, thus, coke production) must be interrupted so that the deposits can be targeted and pushed out of the ovens and into the hot car for disposal. Traditionally, an oven is pulled out of service once every 1-3 years for decarbonization. During those 1-3 years, the deposits have become a near indestructible solid piece of slag that is bound to various interior surfaces of the coke oven, including the floor, sidewalls, and the crown. Much like the hot coke, deposits are extremely hot and exert a large amount of thermal and mechanical stress on the coking machinery. Many conventional coke plants attempt to mitigate damage to the machinery by breaking up large deposits and transporting them to a quench tower for cooling in manageable, smaller portions. However, such an iterative approach takes a long time to remove the waste, thus keeping the ovens/quench tower out of operation and coke production at a halt. In addition, removing the waste in pieces increases the number of transports required of the hot cars, exposing hot cars and/or its individual components to increased amount of thermal and mechanical stress.